JOSE from the command line
jose-demo.sh
#!/bin/bash
# https://tools.ietf.org/html/rfc7515#appendix-C
function create_base64_url {
local base64text="$1"
echo -n "${base64text}" | sed -E s%=+$%% | sed s%\+%-%g | sed -E s%/%_%g
}
function hmac_sha256 {
local base64Key="$1"
local signature_input="$2"
local hexkey base64hmac
hexkey="$( echo -n "${base64Key}" | base64 -d | od -t x1 -An | tr -d '\n ' )"
base64hmac="$( echo -n "${signature_input}" | openssl dgst -sha256 -mac hmac -macopt "hexkey:${hexkey}" -binary | base64 --wrap=0 )"
create_base64_url "${base64hmac}"
}
function json_to_base64 {
local jsonText="$1"
local encoded
encoded="$( echo -n "${jsonText}" | base64 --wrap=0 )"
create_base64_url "${encoded}"
}
function sign_json {
local base64Key="$1"
local jsonPayloadText="$2"
local algorithm header_json header payload signature_input sig
# https://tools.ietf.org/html/rfc7515
# header="$( json_to_base64 '{"alg":"HS256","typ":"JWT"}' )"
algorithm="HS256"
header_json="$( echo "{}" | \
jq --arg x "${algorithm}" '.alg=($x)' | \
jq --arg x "JWT" '.typ=($x)' | \
iconv --from-code=ascii --to-code=utf-8 )"
header="$( json_to_base64 "${header_json}" )"
payload="$( json_to_base64 "${jsonPayloadText}" )"
signature_input="$( echo -n "${header}.${payload}" | iconv --to-code=ascii )"
sig="$( hmac_sha256 "${base64Key}" "${signature_input}" )"
echo "${header}.${payload}.${sig}" | iconv --to-code=ascii
}
function get_current_utc_time {
date --utc +"%Y-%m-%dT%H:%M:%SZ"
}
function generate_request {
local base64Key="$1"
local tenantID="$2"
local subscriptionID="$3"
local timestamp="$4"
local json
json="$( echo "{}" | \
jq --arg x "${tenantID}" '.tenantId=($x)' | \
jq --arg x "${subscriptionID}" '.subscriptionId=($x)' | \
jq --arg x "${timestamp}" '.timeStamp=($x)' | \
jq --arg x '[ "subj" ]' '.claims=($x | fromjson)' | \
jq -c -M | iconv --from-code=ascii --to-code=utf-8 )"
sign_json "${base64Key}" "${json}"
}
base64Key="pDzCAKG9KSaCWY2kLaqf0UWJ89i/gy/6IGvndSWe4eo="
tenantID="chgeuerfte.onmicrosoft.com"
subscriptionID="fb7fdc26-b0e5-45b6-8119-7bc48bc12e4e"
token="$( generate_request "${base64Key}" "${tenantID}" "${subscriptionID}" "$( get_current_utc_time )" )"
echo "${token}"
#
cmd.exe /C "start $( echo "https://jwt.ms/#access_token=${token}" )"